川北早寒武世碳酸盐岩台缘斜坡沉积特征及变形构造形成机制探讨

基于对川北米仓山西部旺苍县鼓城乡唐家河下寒武统仙女洞组露头剖面的观察与镜下分析发现,仙女洞组下段由生物碎屑泥晶灰岩(L)、粉砂质泥岩(M)、似瘤状砾屑灰岩(L')、角砾灰岩(R)、藻凝块灰岩(A)和含生屑钙质砂岩(S)组合而成,其以角砾灰岩、似瘤状砾屑灰岩和藻凝块灰岩为特征,且发育异地岩块和滑塌变形构造。进一步分析认为:L-M岩石组合为正常的斜坡环境低能沉积;L'-R岩石组合中的角砾灰岩为上斜坡生物灰泥丘崩坍滑动至下部而形成的,似瘤状砾屑灰岩可能是由于L-M岩石组合快速沉积导致沉积物失稳滑动变形、上斜坡生物灰泥丘崩落角砾致使的差异压实和滑动、以及后期物质成分差异引起的压溶作用等共同作用的结果,从而使灰质层发生破碎并被泥质包围形成断续的砾屑状,甚至轻微的位移,进而形成条带特征不明显的杂乱变形构造;微生物岩(Mb)组合为上斜坡的灰泥丘沉积;S-M岩石组合为斜坡上部的浊流沉积。根据上述分析结果建立米仓山西部仙女洞组碳酸盐岩台缘斜坡沉积模式,表明仙女洞组沉积早期米仓山西部存在台缘斜坡相沉积。     

河北舍女寺油田女12—女20断块孔二段沉积微相与油气聚集关系研究

黄骅坳陷南部舍女寺油田的古近系孔店组是在断陷盆地的快速充填过程中形成的典型的河流—三角洲沉积。根据取芯井段的取芯和测井资料分析,把剖面结构、砂体几何形态、沉积构造等微相特征进行描述和分析,划分出水下分流河道、河口坝、席状砂等储层沉积微相类型。研究表明,舍女寺地区沉积微相不仅控制储集层的分布,而且控制油气聚集。研究区中较大厚度的油层分布在水下分流河道的中心部位,即该区沉积微相带的主体部位起着油层控制作用。在复杂断块高含水开发中后期,微突起、微断层、微断鼻等圈闭和储集层的有利配置区,尤其是中心微相带与有利的微构造部位叠合区将是有利高产井区。     

Verringerung der Schwermetall‐ und Sulfatbelastung in sauren bergbaubelasteten Gewässern durch Aluminiumpräzipitate

Attenuation of Heavy Metals and Sulfate by Aluminium Precipitates in Acid Mine Drainage During the mixing of acid mine waters with nearly neutral tributaries, often precipitates are formed which are high in iron or aluminium. These precipitates cover the river bed for many kilometres. Near the town of Lehesten (Thuringian slate mining area), leachates of slate quarries and waste rock dumps contain high amounts of aluminium, sulfate, copper, nickel, zinc, manganese, and H⁺ ions as a result of the oxidation of incorporated pyrite. These leachates enter the brooks Loquitz, Kleine Sormitz, and Rehbach leading to the phenomenon named above. The contribution of the forming aluminium‐rich precipitates on the attenuation of sulfate and heavy metals by sorption or coprecipitation was studied by analysing the composition of water and sediment samples as well as samples of suspended matter. Sulfate is often considered as conservative tracer in acid mine drainage. However, sulfate does not behave conservatively in this system what might be explained by the adsorption of sulfate to the aluminium precipitates. Instead, conservative behaviour was found for calcium, potassium, chloride, zinc, manganese, and nickel. A formation of jurbanite can be excluded because of the low sulfate contents. The sulfate content of the sediment depends on the pH. At low pH values (4.8) the S/Al ratio corresponds to the theoretical ratio in basaluminite and decreases with rising pH. Sulfate is weakly bound to the solid phase and can easily be replaced by OH^– ions. A formation of basaluminite is possible at low pH values with a fluent transition to aluminium hydroxide. Therefore the precipitates are assumed to consist predominantly of aluminium hydroxide with sulfate being adsorbed to the surface.     

Dissolved Carbohydrate Concentration,Composition, and Bioavailability to Microbial Heterotrophs in Stream Water

Dissolved total carbohydrates (DTCH), dissolved free monosaccharides (DFMS), dissolved organic carbon (DOC), biodegradable DOC (BDOC), and humic substances (HS) were measured in White Clay Creek (WCC), a stream in southeastern Pennsylvania Piedmont, USA. Samples were collected over different seasons and under baseflow and stormflow conditions. DOC concentrations ranged from 1.0 to 12.8 mg/L C with the highest concentrations associated with stormflows. Carbohydrates ranged from 0.42 to 12.4 μM and accounted for 2.9 to 12.7% of the DOC. Humic substances represented the major DOC fraction, accounting for 55 to 72% of the DOC pool under all flow conditions. The humic fraction had a lower carbohydrate content (4.4%) than the non-humic fraction of DOC (7.2%). Stormflow DOC was enriched in carbohydrates relative to baseflow DOC, but the percentage of humic-C changed little. Carbohydrates were primarily present as dissolved polysaccharides (55%), but a significant fraction was bound to humic substances (40%), while a small proportion was present as monosaccharides (5%). The major monosaccharides in stream water, listed in order of decreasing concentration, included glucose, galactose, rhamnose, xylose, arabinose, mannose, and fucose. On average (30.6 ± 7.4)% (n = 44) of the stream water DOC was biodegradable, and carbohydrates accounted for 9.9 to 17.7% of the BDOC.     

Tracing of Peroxidase Activity in Humic Lake Water

An enzyme assay was developed for studies on peroxidase activities in humic lake water. 3,4-Dimethoxybenzyl alcohol (veratryl alcohol, VeraOH) was used as tracer substrate, and peroxidase (EC 1.11.1.7) activity was measured by high-performance liquid chromatography. The chemical stability of VeraOH and its application as peroxidase substrate was tested under light and dark conditions, different hydrogen peroxide (H₂O₂) concentrations and humic matter contents. VeraOH was stable under low UV radiation at in situ conditions in lake water (<0.010...0.25 kJ m^–2 d^–1), laboratory conditions (<0.05...0.30 kJ m^–2 d^–1), and low (1...100 μM) H₂O₂ concentrations. However, peroxides oxidized VeraOH above 1...10 mM H₂O₂ concentration in sterile Millipore-Q and humic lake water. Dark incubations showed little VeraOH oxidation products. The developed peroxidase assay was tested in the growth medium of Phanerochaete chrysosporium and a bacteria isolate (P.M.D. 20.4.3.1) from mesohumic lake Pääjärvi. Peroxidase activities were also measured in natural microbial communities under standard laboratory and under in situ conditions in humic lake water. Incubation times of about 5 to 12 days were usually needed to record significant (P < 0.05) peroxidase activities, in lake waters. In situ peroxidase activities varied in pelagial surface water (0...0.5 m) on a seasonal scale between 74 nmol L^–1 h^–1 and 273 nmol L^–1 (mean: 176 nmol L^–1 h^–1) and within the water column between 110 nmol L^–1 h^–1 and 800 nmol L^–1 h^–1 (mean: 500 nmol L^–1 h^–1) in polyhumic lake Mekkojärvi.     

Urease-Hemmtest für wirkungsbezogene Untersuchungen der Bindungsformen von Kupfer in Wässern und Bodeneluaten

Urease Inhibition Test for Effect-related Investigations of Copper Speciation in Water and Soil Extracts In 80 different water samples, the inhibition effect of cupric ions was measured by application of a simple urease inhibition test. In relation to the total copper concentration, the inhibition permits an effect-related classification of drinking water, rain water, spring water, surface water, leakage water, wastewater, and soil extracts. Drinking water contains high parts of cupric ions in the free hydrated form. Their copper content results in high urease inhibition and is caused by using copper pipes in house plumbing. In leakage water, wastewater, and soil extracts, cupric ions are mainly complexed by organic compounds in the sample matrix. Hence, the inhibition effects are low. In soil extracts, the urease inhibition increased after an UV-decomposition procedure, but a decreasing effect was observed for a surface and a drinking water sample, respectively. The chemical oxygen demand and UV-absorbance at 255 nm measured before and after the procedure were correlated to the content of organic compounds, i.e., humic acid. In most samples, the organic matrix was not decomposed completely. The oxidizing decomposition apparently forms further complexing agents, which suppress the inhibition effect of cupric ions. In the rain water samples investigated, the content of organic compounds depended on rain intensity. The chemical oxygen demand and UV-absorbance, respectively, were low for rain water collected during strong rain periods and increased with decreasing rain intensity. The rain water trickled over sheet-lead roof showed an increase of urease inhibition compared with the simultaneously collected rain. Consequently, a decomposition of organic matrix could be demonstrated in rain water by use of the urease inhibition test.     

Last interglacial-glacial cycle and an attempt to reconstruct Würmian paleohumidity of the European Alps

A lot of paleoenvironmental surveys have been carried out in the Alpine region to elucidate glacier extension during the Last Glacial or the Würmian (115 - 12 ka BP). However, the evidence of past glaciations differs greatly between Western and Eastern Alps, while contrast between Southern and Northern Alps is not evident. The main purpose of this paper is to interpret variability of humidity during the last interglacial-glacial cycle in the Alpine region, based on results of various surveys performed in the Alpine region. Results show that distribution of moisture throughout the Alps was most even during the Late Würmian, while precipitation was mainly concentrated in the (North)Western Alps during the Early Würmian and in the (North)Western and along all the Southern Alps during the Middle Würmian. The Eastern Alps were rather dry during both episodes. Such moisture distribution can be explained by paths of prevailing winds. Moisture distribution is directly linked with atmospheric and oceanic circulation.     

天山乌鲁木齐河源1号冰川径流对气候变化的响应分析

利用天山乌鲁木齐河源1号冰川1959-2006年的气象、冰川物质平衡和1980-2006年的水文资料,分析了其冰川径流的变化.结果表明:由于1996年以来的显著升温,导致了1号冰川水文点径流主要受夏季气温变化的控制,冰川物质损失对径流的补给作用已超过了降水的作用.1996-2006年与1980-1995年相比,夏季气温...     

西藏察隅县那阿钨床成矿地质特征与找矿前景

那阿钨矿为矽卡岩型白钨矿床,矿体产于沿北西向分布的二长花岗岩岩体与大理岩的外接触带的矽卡岩及其强矽卡岩化大理岩中,其规模、形态、产状严格受矽卡岩岩性控制,自南向北矿体埋藏深度逐渐加大,向深部钨矿化有变好趋势。围岩蚀变主要有矽卡岩化、硅化及碳酸岩化等。通过对矿区的成矿地质条件进行分析,总结分析了区内找矿及成矿标志,提出了有益建议。     

陕西略阳煎茶岭金矿床成矿作用探讨

煎茶岭金矿床位于勉略宁三角区东北缘,矿体产于环绕超基性岩体分布的含金蚀变带中,属蚀变岩型矿床。由于对其成矿作用认识分歧较大,严重影响了后续的找矿勘探工作。从矿床地质特征入手,通过矿区岩矿石常量元素、微量元素、稀土元素以及硫、氢、氧同位素的测试分析,探讨其控矿因素和成矿机理。结果表明,矿床受叠加于接触带部位的韧脆性剪切带控制,成矿不仅与超基性岩有关,而且与花岗斑岩关系密切。花岗斑岩的侵入引起超基性岩的彻底蚀变,同时导致原岩中的金等成矿物质被释放出来。矿石、蚀变超基性岩、白云岩中黄铁矿的硫同位素组成与花岗斑岩中黄铁矿的硫同位素组成具有较好的一致性,并表现出一定的规律性,说明花岗斑岩提供了成矿所需的硫;矿石氢、氧同位素组成介于岩浆水与大气降水之间,且多数样品聚集在雨水线附近,暗示花岗斑岩提供了初始热液,随着成矿作用的进行,大气降水不断加入,从而形成复合热液。鉴于矿床与花岗斑岩的密切关系以及铬云母化的产出特点,根据同位素年龄,认为矿床形成于印支中期—燕山中期。